Freight container transfer system

ABSTRACT

A FREIGHT CONTAINER TRANSFER SYSTEM WHEREIN AN ELONGATED RACK IS DETACHABLY CONNECTABLE BETWEEN A PUSH-PULL TRANSFER MOTOR ON A TRANSFER VEHICLE AND THE BASE OF A FREIGHT CONTAINER. THE RACK HAS A MOVABLE STOP ON ITS UPPER SURFACE, SELECTIVELY ENGAGEABLE WITH A CONTAINER BASE, AND A SERIES OF OPENINGS IN ITS LOWER SURFACES ENGAGEABLE SUCCESSIVELY WITH A RATCHETING ACTION, BY THE PUSH-PULL MOTOR ENABLING THE CONTAINER TO BE TRANSFERRED OVER THE SIDE OF THE TRANSFER VEHICLE. A SET OF SLIDABLE SUPPORT BOLSTERS ON THE TRANSFER VEHICLE, EXTENDIBLE AND RETRACTABLE OVER THE SIDE THEREOF, FACILITATE THE TRANSFER OPERATION.

May 23, 1972 A. M. HAND FRIEGHT CONTAINER TRANSFER SYSTEM 3 Sheets-Sheet 1 Filed Dec. 8, 1969 INVENTOR.

ALBERT r1. HAND .92,

May 23, 1972 A. M. HAND FRIEGHI CONTAINER TRANSFER SYSTEM 3 Sheets-Sheet 2 Filed Dec. 8, 1969 INVENTOR.

ALBERT M. HAN D BY v Agen May 23, 1972 HAND 3,664,533

FRIEGHT CONTAINER TRANSFER SYSTEM q so rung-W F167 10 FIG. 8

INVENTOR. I

ALasrr M. Hmvn BY United States Patent 3,664,533 FREIGHT CONTAINER TRANSFER SYSTEM Albert Michael Hand, York, Ontario, Canada, assignor to Steadman Industries (Nassau) Limited, Nassau, The Bahamas Filed Dec. 8, 1969, Ser. No. 882,893 Int. Cl. B60p 1/64 US. Cl. 214516 15 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a freight container transfer system of the type including a transfer vehicle for carrying one or more containers thereon and having transfer facilities operable for effecting transfer of the or each container between said vehicle and a support adjacent the vehicle. Such transfer may also be effected to move the or each container between two adjacent supports not themselves equipped with transfer facilities by utilizing the vehicle of the invention as an intermediate bridging element in the transfer operation. Such support as mentioned herein preferably include support surfaces for supporting said containers thereon with which the support portion of the transfer vehicle is alignable; such support surfaces being provided on, for example, a loading quay, a railway vehicle, a truck, or road semi-trailer, any of which may or may not be provided with transfer facilities.

Known forms of container transfer system include the provision of specially constructed containers having means thereon for co-operative engagement by the transfer facilities of a transfer vehicle. Such means may take any of several forms, one known form comprising an elongated rack, provided with spaced openings therein, secured to the underside of the container; said openings being engageable by the transfer facilities to effect transfer to and from the transfer vehicle.

It is a broad object of the present invention to provide a container transfer system including a transfer vehicle having transfer means thereon operable relatively universally for effecting transfer of containers thereto or therefrom irrespective of whether the containers themselves are specifically built for co-operation with such transfer means.

It is a further object of the invention to provide such a container transfer system including a transfer member detachably engageable with many types of container, which member is itself engageable by transfer means on a transfer vehicle whereby transfer of the container itself may be effected. It is a yet further object to provide a container transfer system wherein the transfer member is in the form of a rack having a plurality of spacedapart openings or the equivalent therein for engagement with a reciprocable pawl constituting a part of the transfer means aforesaid; stop means being provided on said transfer member for engagement with an edge of the container for effecting transfer as aforesaid and wherein said means are remotely operable.

3,664,533 Patented May 23, 1972 ice It is also an object to provide a container transfer system wherein support means are provided on the transfer vehicle for supporting the base of the container thereon, said support means being in the form of elongated bolsters which are extensible and retractable over the sides of the vehicle for bridging the space normally existing between the vehicle and the support surface to or from which a container is being transferred.

In accordance with the invention, there is provided a container transfer system including, in combination, a transfer vehicle, for supporting a container thereon and an elongated transfer plate carried on the vehicle detachably engageable with the container. Said plate is provided with a plurality of spaced-apart openings or the like engageable by transfer means carried on the transfer vehicle, said transfer means including a pawl operable for ratcheting engagement with said plate in step-by-step operation to effect transfer of the container, when the plate is engaged therewith, to or from the transfer vehicle.

Other objects of the invention more or less broad than the foregoing will become apparent from the hereinafter following description of the elements, parts and principles thereof given herein solely by way of example with reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views and wherein:

FIG. 1 is a top perspective view of a road transfer vehicle and transfer equipment constructed in accordance with the invention showing, also, partly cut-away, a freight container useable therewith;

FIG. 2 is a similar view to FIG. 1 showing an intermediate stage in the transfer of the freight container off the side of the road vehicle;

FIG. 3 is an underneath perspective view of the transfer plate constituting part of the transfer equipment shown in FIG. 1;

FIG. 4 is a top perspective view of the transfer plate shown in FIG. 3;

FIG. 5 is a side view of a further part of the transfer equipment showing the relative interengagement between a transfer motor, the transfer plate and the freight container;

FIG. 6-8 are somewhat diagrammatic end views showing successive stages in the transfer of a freight container from a rail car to a road transfer vehicle.

The instant invention relates to that type of container transfer system including a transfer vehicle 10 having transfer facilities associated therewith enabling one or more containers 12 carried on the vehicle to be transferred to or from an adjacent support surface. The type of transfer vehicle 10 contemplated herein not only enables simple transfer therefrom or thereto of a container 12 as aforesaid but also permits its use as a bridge whereby a container 12 may be transferred between two support surfaces via 1the bridging intermediary of a said transfer vehice 0.

Such a transfer system as described above is not in itself new and, for exemplary purposes herein, attention is directed to the US. Pat. No. 3,219,218 to Hand issued Nov. 23, 1965 which discloses, inter alia, a transfer vehicle having push-pull transfer piston and cylinder assemblies for co-operation with a rack in the form of an apertured transfer plate provided on the underside of a container base; transfer being effected in a step-by-step manner by ratcheting action of the piston of one of said piston and cylinder assemblies relative to a container rack.

The containers disclosed in the aforeesaid US. Pat. No. 3,219,218 have their racks fixedly attached to or integral with the container base and are specifically designed for co-operation with the transfer facilities aforesaid. Thus, only those specific containers provided with racks can be utilized in conjunction with the transfer vehicle.

In accordance with the inventive concept herein, the transfer system of the instant invention includes a transfer plate 14 detachably engageable with a container 12 and is itself co-operatively engageable by a transfer motor 16 carried on a transfer vehicle 10. By the provision of a transfer plate which is detachably engageable with a container 12, there is provided, what may be termed, a universal transfer system whereby any type of container 12, appropriately dimensioned to suit the transfer vehicle 10, may be transferred therefrom or thereto irrespective of whether or not it is specifically designed for co-operation with, or to form a part of, the specific transfer system carried by the vehicle 10.

As stated hereinbefore, the transfer facilities of interest to the invention are provided on a transfer vehicle which will usually be a road trailer or semi-trailer, as illustrated herein, but which, conceivably, could be any other type such as a rail vehicle or even a fixed support surface as at a loading quay or wharf. Such facilities are comprised of at least one transfer motor 16 operable to effect step-by-step movement of a container 12 through the intermediary of a transfer plate 14 detachably engaged with a container 12.

As illustrated herein and clearly shown in FIGS. 1 and 2, the transfer vehicle 10 comprises a road semi-trailer equipped with two opposed transfer motors 16 for effecting transfer of a container 12 over either side of the vehicle. A complete description of such a road semitrailer and transfer motors is contained in the aforesaid US. Pat. No. 3,219,218 and, for the purposes of the instant specification, it is sutficient to note, referring particularly to FIG. 5, that the semi-trailer 10 includes a chassis 18 mounting an opposed pair of transfer motors 16 thereon; each motor being of the piston and cylinder type 20-22 having plate engaging means in the form of a pawl 24 at the free end of each piston rod 22. Each such piston and cylinder assembly 20-22 is spring-biased upwardly to press the pawl 24 into engagement with the plate, when positioned for co-operation therewith as will be more fully described herein, and each pawl 24 is rotatable about the axis of its piston rod 22 through 180 for positioning it selectively for pushing or pulling action relative to the plate 14.

The transfer plate 14 of the instant invention is normally carried on the transfer vehicle 10 and is positionable relative to a container 12 to be transferred either to or from the vehicle 10 so as to be detachably engageable with the container 12 either in a push or pull position for operative engagement itself by a transfer motor 16.

Referring ot FIGS. 3 and 4, the transfer plate 14 herein is in the form of an elongated box-like member of a length such as to exceed the maximum width of the container 12 to be transferred and carrying stop means 26 thereon movable between operative and inoperative positions whereby the plate 14 may be detachably engaged with a container base. More particularly, the plate 14 is comprised basically of an elongated channel-section member having a base 28 and two integral parallel side walls 30; the channel together with an elongated top member 32 welded along its edges to the outer edges of the side walls imparting a hollow box section to the transfer plate 14. The adjacent end portions of the top member 32 and the base 28 are convergent relative one to another so as to provide, at each end 34 of the plate 14, a substantially wedgeshaped configuration. The base 28 of the plate 14 is, in this embodiment, in the form of a rack provided with a plurality of longitudinally spaced-apart substantially rectangular openings 36 affording ratchet means of engagement for a said pawl 24 of a transfer motor 16; the spacing between adjacent openings being no greater than the maximum stroke of each transfer motor.

The stop means 26 conveniently comprises a rigid stop plate, preferably stiffened by appropriate bracing, and pivotally mounted within the plate 14 adjacent one end thereof so as to project upwardly, in an operative position, through an opening in the top member 32 thereof and to be retractable, to an inoperative position, to lie flush with or below said top member 32. Remote control means are coupled to the stop 26 for selectively moving it from its said inoperative to operative positions and vice versa.

In the embodiment herein, the stop 26 is fixedly secured, as by welding, at its lower forward corners to a relatively large diameter pivot pin 38 journalled within the side walls 30 of the plate 14 whereby pivoting movement of the stop 26 is accommodated. As stated above, in the inoperative position of the stop 26, it is pivoted clear of the top member 32 whilst movement of the stop 26 towards its operative position is checked at the actual operative position by an abutment comprised of the edge 40 of the opening in the top member 32 against which the stop 26 can rest in said operative position.

The aforesaid remote control means for the stop 26 is comprised of an elongated rod 42 extending from a position adjacent the stop 26 to a position, at which it may be manually operated, adjacent that end of the plate 14 remote from the stop 26; said rod being coupled to the stop 26 in such manner that sliding movement of the rod 42 relative to the plate 14 procures the desired pivoting movement of the stop 26. As illustrated herein in FIGS. 3 and 4, movement of the rod 42 towards the stop 26 procures upward pivoting movement thereof from its inoperative towards its operative position whilst movement of the rod 42 away from the stop 26 procures downward pivoting movement thereof towards its inoperative retracted position.

Said coupling between the rod 42 and the stop 26 is preferably comprised of a lever 44 fixedly secured, as by welding, at its one end to an integral extension of the aforesaid pivot pin 38 and is apertured at its upper end side walls 30. Such lever 44 extends generally upwardly from said pivot pin 38 and is apertured at its upper end providing a bearing for a further pivot pin 46, each end of which is fixedly secured, as by welding, to one end of a clevis linkage 48; the other ends of said linkage 48 being secured to the end of the control rod 42.

The rod 42 is mounted for sliding movement as aforesaid relative to the transfer plate 14 within an elongated sleeve 50 secured thereto as by welding whilst that end of the rod 42 remote from the stop 26 is cranked to form a handle 52 facilitating the aforesaid sliding operation of the rod 42 to pivot the stop 26 as required. As shown in FIG. 4, said handle 52 is pivotally connected at one end to a clevis yoke and pivot pin assembly 54 on the end of the control rod 42 and is further pivoted on pin 56 on the top member 32 of the transfer plate 14; the adjacent end of member 32 being appropriately cut away to facilitate actuation of handle 52.

The transfer plate 14 together with its stop 26 and control rod 42 is normally carried on a transfer vehicle 10, in this embodiment, the road semi-trailer aforesaid, and is preferably rotatably mounted thereon for swinging movement in a horizontal plane between a stored positron in which it is generally parallel to the longitudinal axis of the vehicle chassis (see FIG. 1) and an operative position in which the rack is generally perpendicular to the axis of the vehicle chassis (see FIG. 2). The transfer plate 14 is preferably carried on a guideway 58 which is conveniently of channel-section for accommodating sliding movement of the plate 14 thereon and which is mounted for rotation as aforesaid upon a suitable bearing 60 carried on the vehicle chassis. If desired, means may be provided for raising and lowering the guideway 58 relative to the vehicle chassis 18 whilst still permitting rotary movement of the guideway 58 and sliding movement of the plate 14 thereon as aforesaid.

It will be appreciated that, when the plate 14 is in its operative position perpendicular to the axis of the vehicle chassis 18 (see FIG. 2), the rack base 28 of the plate 14 lies directly above the transfer motors 16 whereby the pawl 24 of either one of the said two opposed motors 16 may selectively be brought into cooperative engagement with co-operating means on the rack base 28, specifically, as illustrated herein, the openings 36. As is disclosed in US. Pat. No. 3,219,218, each transfer motor 16 is normally held in a lower retracted position by means of a toggle locking mechanism 62 releasable to permit the pawl 24 to co-operatively engage with the rack base 28 under the resilient influence of a coil compression spring 64. Thus, when one or other of the transfer motors 16 is released from its retracted operative position so that its pawl 24 is brought into engagement with the rack base 28, said rack base 28 may then be advanced by such motor 16 and extended over the side of the transfer vehicle as will be further described herein.

Before elaborating in detail on the sequence of events which are carried out during the transfer of a container 12 to or from the transfer vehicle 10, it should be pointed out that it is necessary that the container support level of the vehicle 10 and the support surface to or from which the container 12 is to be transferred are substantially coplanar with one another. It is conventional to equip the transfer vehicle 10, such as the road semi-trailer described herein, with elongated bolsters 70 (see FIGS. 1 and 2) extending transversely across the width of the vehicle and spaced apart to support the container base adjacent its ends. Support bolsters 72 may also be provided upon the support surface (see FIGS. 1 and 2) to or from which the container 12 is to be transferred although, in some instances, it is possible that no bolsters will normally be provided. Also, there is by no means any uniformity in the configuration of the bases of the various containers which may be required to be transferred by the instant transfer system and, whilst some containers may be provided with bases having substantially plane undersurfaces (for support on such as bolsters 72) other container bases may be provided with rigid corner castings projecting downwardly below the general plane of the container base (for support on such as a plane support surface). The instant invention seeks to provide facilities for the transfer of different types of containers to and from different types of support surfaces and such facilities will become apparent as the hereinafter following description proceeds.

Considering now the transfer of a container 12 from a support surface to a transfer vehicle 10 of the road semi-trailer type and referring to FIGS. 68, it is, first of all, required to position the semi-trailer with the axis of the vehicle chassis 18 substantially parallel to the adjacent side of the container 12 and, generally, to elevate the semi-trailer 10 so that the bolsters 70 carried thereon are co-planar with the support surface upon which the container 12 rests, whether it be bolsters 72 as illustrated herein or a plane flat surface. To achieve this, the semitrailer 10 may be elevated and supported upon hydraulically-actuated jacks 74 such as those described in the aforesaid US. Pat. No. 3,219,218.

After such positioning and orientation, the transfer plate 14 is rotated from the storage position as shown in FIG. 1 to lie perpendicular to the axis of the vehicle chassis 18; it being understood that the aforesaid positioning of the semitrailer 10 will be such as to position the transfer plate 14 approximately opposite and adjacent the centre of one side of the container 12. That transfer motor 16 adjacent to the container 12 is then released from its retracted inoperative position so that its pawl 24 will bear against the rack base 28; the pawl 24 being positioned for pushing operation upon the rack base 28. Extension of the piston rod 20 carrying the pawl 24 will cause it to engage with the first adjacent opening 36 in the rack base 28 and further extension of the piston rod 20 will slide the transfer plate 14 outwardly over the side of the semi-trailer 10. Upon reaching the limit of its stroke, the piston 20 is retracted and, due to the shape of the pawl 24 and the spring bias acting thereon, the pawl 24 will be retracted with a ratcheting action relative to the openings 36 in the rack base 28. Such back and forth operation of the piston 20 is continued to move the transfer plate 14 outwardly in step-by-step manner, through the position shown in FIG. 6, until the leading end thereof has passed underneath the container 12 on its support surface and emerged on that side of the container 12 remote from the transfer vehicle 10; it being understood that the aforesaid stop 26 is carried on the leading end of the transfer plate 14.

As aforesaid, some discrepancies may arise as to the clearance between the undersurface of the container base and the actual support surface on which it rests according to the type of bolsters in use or the configuration of the container base itself. Thus, if an over-large clearance is provided between the undersurface of the container base and the plate surface carrying the bolsters upon which the container rests, it may be necessary to introduce auxiliary support means such as a ramp, not illustrated, to support the transfer plate 14 when it is located underneath the container base.

When the transfer plate 14 is positioned as aforesaid with its leading end projecting from that side of the container 12 remote from the transfer vehicle 10, the control rod 42 is manually actuated by handle 52 to move it in a forward direction to raise the stop 26 to its operative position (see FIG. 7).

The aforesaid transfer motor 16 is then retracted and locked in its inoperative position whilst its pawl 24 is rotated through whereupon the motor 16 is released to its operative position ready for pulling the transfer plate 14 in a direction towards the semi-trailer chassis 18. This pulling operation is carried out in exactly the same manner as the aforesaid pushing operation to withdraw the plate 14 in a step-by-step manner back onto the vehicle chassis 18. However, the projecting stop 26 upon the upper surface of the transfer plate 14, at what will now be its trailing end, will now engage the side edge of the container 12 remote from the transfer vehicle 10 so that pulling of the plate 14 towards the vehicle chassis 18 will also pull the container 12 with it through the position shown in FIG. 8. Thus, the ratcheting action of the transfer motor 16 is continued until the transfer plate 14 is retracted far enough to position the container 12 upon the vehicle chassis bolsters 70 at which time the transfer operation is deemed to be substantially complete. It should, of course, be appreciated that a similar operation can be effected to transfer a container 12 from the transfer vehicle 10 to an adjacent support surface either over that same side of the vehicle chassis 18 as has just "been described or over the other side thereof; the transfer plate 14 being appropriately rotated prior to the tansfer operation to position its stop 26 at the trailing end thereof so that it may procure pushing of the container 12 off the transfer vehicle 10, a mid-way stage in such a pushing operation being shown in FIG. 2. Thus, by actuation of the two transfer motors 16 in sequence, the transfer vehicle 10 may, if desired, be used as a bridge, facilitating the transfer of a container 12 from one adjacent support surface on one side of the vehicle to another support surface on the other side thereof. It will be understood that in such a bridging operation, the stop 26 on the transfer plate 14 will initially procure pulling of the container 12 onto the transfer vehicle 10 and will subsequentlyly proceure pushing of the container 12 off the said vehicle.

As has been mentioned hereinbefore and as illustrated herein in FIGS. 1 and 2 and 6 to 8, some containers 12 are provided with rigid corner castings 76 which project below the general plane of the undersurface of the container base and it is apparent, that when such containers 12 are being transferred as aforesaid, the whole container will tend to tilt when it has been transferred sufficiently far to enable the corner castings 76 to clear the bolsters upon which they normally rest. Thus, when transferring such a type of container, it is necessary to provide a continous bridging connection between the support surface from which the container is being transferred and the transfer vehicle itself.

To this end, the instant system contemplates the provision of bolsters 70 provided on the transfer vehicle which are telescopic transversely of the chassis 18 to bridge the gap between the vehicle and the adjacent support surface, herein shown as bolsters 72. Thus, when transferring a container 12 from a support surface to the transfer vehicle 10 as aforesaid, before the actual transfer operation commences, such bolsters 70 would be extended until they abutted the support surface at which time the container 12 could be pulled towards the transfer 7 vehicle 10 onto the extended bolsters. Withdrawal of the transfer plate 14 towards the transfer vehicle 10 would then be continued substantially as described above until the container 12 was fully supported upon the vehicle bolsters 70 at which time they would be actuated under power to retract to their symmetrical central positions on the transfer vehicle chassis 18, carrying the container 12 with them to centre it.

As illustrated herein in FIGS. 1 and 2, a telescopic bolster 70 is provided at each end of the vehicle chassis 18 actuated by power means such as a hydraulic piston and cylinder unit 78 so mounted with respect to the extensible portion of the bolster that said portion may be moved to project over either side of the vehicle chassis 18 to bridge the gap which will normally exist between the vehicle 10 and an adjacent support surface 72 to or from which a container '12 is being transferred.

As has been mentioned above, the road semi-trailer 10 is provided with bolsters 70 so located as to support the ends of containers 12 to be transferred thereto or therefrom and thus, if, as illustrated herein, a single long container is to be carried on the semi-trailer, two bolsters will be provided thereon, one adjacent each end of the trailer chassis 18. Inasmuch as both of the bolsters are of similar construction and operation, for the sake of convenience herein, only one such bolster 70 will be described in more detail.

Referring now to FIGS. 1 and 2, a bolster 70 is com prised of two parts, namely, a rigid girder 80 extending transversely across one end of the vehicle chassis 18 and a sliding bolster proper 82 mounted for sliding movement on the girder 80. The girder 80 is comprised of a rigid transverse box section member whilst the sliding bolster 82 is also of a rigid box cross-section having integral flanges 84 extending outwardly on both sides of its base and extending substantially over the full length of the bolster. The girder 80 carries guide plates 86 on its upper surface spaced upwardly therefrom to afford guideways for the bolster flanges 84- thereby accommodating sliding movement of the bolster 82 in a longitudinal direction thereof and transversely of the vehicle chassis 18.

The bolster 82 is powered for sliding movement as aforesaid, preferably by means of the hydraulic motor 78 illustrated herein. Such hydraulic motor is herein of the piston and cylinder type wherein the free end of its piston rod 88 is secured to the sliding bolster 82 and the cylinder 90 is secured to the girder 80 by suitable supporting brackets; the positioning and orientation of the piston and cylinder assembly 88-90 being such that the piston 88 is extended to half of its stroke when the bolster 82 is centered relative to the vehicle chassis. Such an arrangement ensures that the bolster 82 can be slidably extended over either side of the vehicle chassis *18 by either retraction or extension respectively of the piston rod 88 relative to its cylinder 90.

For locking the container 12 in position on the semitrailer 10, end stops 92 of conventional form are provided 8 pivotally mounted on the bolster 70 and swingable upwardly to be locked in position; such stops conveniently being of the type as described in the aforesaid US. Pat. No. 3,219,218.

The function of the sliding bolster assembly 82 enhancing the instant transfer system has been described hereinbefore but, despite these improved facilities, under some conditions the transfer vehicle 10-, in this instance the road semi-trailer, may tend to move away from the adjacent support surface, to or from which a container 12 is being transferred, during the actual transfer operation. To overcome this disadvantage, restraining means 94 are provided on the transfer vehicle 10 which are connectable between the vehicle 10 and the adjacent support surface for restraining such movement as aforesaid and, in the present embodiment, such restraining means 94 are in the form of the heavy duty chains shown in FIG. 2 connectable between the transfer vehicle 10 and the said support surface.

What I claim is:

1. In combination: a transfer vehicle including means for supporting the base of a freight container thereon;

a transfer motor on said vehicle including a head reciprocable in a direction transversely of the vehicle for effecting transfer of a said container over the side of said vehicle either to or from an adjacent supporting surface at a corresponding level to said support means, and

an elongated transfer member disposable on said vehicle, said head being resiliently biased into engagement therewith and movable relative thereto by said motor with a ratcheting action to procure extension and retraction of said member over a side of the vehicle in a step by step manner; said member also being selectively engageable with a said container for pushing or pulling it respectively over said vehicle side when said member is engaged with an actuated by said motor as aforesaid.

2. The combination as claimed in claim 1 including:

a guideway pivotally mounted on said vehicle and on which said transfer member is slidable,

said guideway and transfer member being movable between a stored position in which said transfer member does not extend over the sides of said vehicle and an operative position in which said transfer member is engageable by said motor head as aforesaid.

3. The combination as claimed in claim 1 wherein:

the transfer member is disposable on said vehicle above said motor for engagement of said head with the undersurface of said member.

4. The combination as claimed in claim 1, including:

a stop adjacent one end of said transfer member movable between operative and inoperative positions; said stop in said inoperative position permitting location of said transfer member underneath a said container and, in said operative position, being engageable with said container for procuring movement thereof upon said actuation of said head when said motor is engaged with said transfer member.

'5. The combination as claimed in claim 4 wherein:

said stop is disposable flush with the upper surface of said transfer member in said inoperative position and is raisable above said surface in said operative position for engagement with a side edge of the base of a said container.

6. The combination as claimed in claim 4 including:

control means on said transfer member operable, at

that end thereof remote from said stop, for moving said stop between said operative and inoperative positions.

7. The combination as claimed in claim 1 wherein:

said transfer member is provided with a plurality of spaced apart openings on the undersurface thereof locatable above said motor head when said transfer member is disposed on said vehicle,

said head being engageable with successive said openings to effect said extension and retraction of said transfer member upon actuation of said motor.

8. The combination as claimed in claim 1 wherein:

said head is selectively positionable relative to said transfer member to effect said extension or retraction thereof upon reciprocation of said head by said motor.

9. The combination as claimed in claim 1 wherein:

said motor comprises a fluid pressure-operated piston and cylinder assembly,

said head being carried on the free end of a piston rod reciprocable relative to the motor cylinder;

said cylinder being pivotally mounted on said vehicle and being resiliently biased upwardly relative thereto procuring engagement of said head with said transfer member when said member is disposed on said vehicle above said motor. 510. The combination as claimed in claim 9 wherein: said head comprises a double-ended pawl rotatable through 180 about the axis of said piston rod, the said ends of said pawl being respectively configured to procure either extension or retraction of said transfer member upon reciprocation of said piston rod relative to said cylinder.

11. The combination as claimed in claim '1 wherein:

said support means on said vehicle. comprises a pair of bolsters extending transversely thereof for supporting the base of a said container adjacent 1ts ends.

12. The combination as claimed in claim 11 wherein:

each said bolster is extendable and retractable over the side of the vehicle to provide, in its extended position, a bridging connection between said vehicle and a said adjacent supporting surface to or from which a said container is transferable.

13. The combination as claimed in claim 12 wherein:

each said bolster comprises a guide fixedly mounted on said vehicle, and

a bolster proper supporting the container base slidably mounted within said guide.

14. The combination as claimed in claim 13 comprising:

power-operated means connected between said guide and said bolster proper operable to effect extension and retraction of said bolster proper over the vehicle side.

15. The combination as claimed in claim 14 wherein:

said power-operated means comprises a fluid pressureoperated piston and cylinder assembly.

References Cited UNITED STATES PATENTS Re. 20,760 6/1938 Ludington 214-5 16 3,357,582 12/1967 Wittek 21438 C X 3,219,218 11/1965 Hand 214---516 ROBERT G. SHERIDAN, Primary Examiner U.S. Cl. X.R. 

